1. Field of the Invention
The present invention relates to a transportation and utilization system which effectively transports geothermal hot water present underground up to the ground surface. More particularly, it is directed to the provision of a transportation and utilization system in which a downhole pump is provided in a production well where the geothermal hot water is present and this downhole pump is driven by a two-phase flow turbine to transport the geothermal hot water up to the ground surface while preventing evaporation thereof.
2. Description of the Prior Art
A wide variety of systems have recently been developed to utilize geothermal hot water for power generation. The geothermal hot water may be saturated under certain pressure. Accordingly, when the pressure is lowered, the geothermal hot water will flash, causing loss of energy contained in the geothermal hot water as much as it evaporates.
For this reason, the important thing to effectively utilize the geothermal hot water is not to lose energy contained therein by preventing its evaporation when being transported.
Underground geothermal hot water undergoes evaporation which turns into steam, which steam spouts out of the ground in the form of mist. When the geothermal hot water is turned into the steam, the temperature is lowered by 15 to 16% since part of energy contained therein may be consumed as mentioned above. Correspondingly, pressure of the geothermal hot water may be lowered and energy is lost as much.
Furthermore, when the geothermal hot water evaporates and is turned into the steam, the volume of the steam becomes considerably larger than that of the geothermal hot water. Therefore, the transportation thereof must deliberately be considered.
For the reasons as mentioned above, high temperature (high pressure) of the geothermal hot water is obtained by preventing evaporation thereof in the ground. Thus, energy contained in the geothermal hot water may be utilized to a full extent.
The geothermal hot water constitutes an integral part of the geothermal-power generation. It is already known that the most effective system to obtain such geothermal hot water is to install a downhole pump in a geothermal production well below the evaporation water level.
However, even if the downhole pump is installed as mentioned above, no power supply system is normally provided where the geothermal hot water is present. In addition, when an internal combustion engine is employed as power source, transportation and maintenance of fuel become a problem.